Considerations around installing Solar

[fromdownwest]

I am looking at the option of a solar install via Octpus.

 

I have been quoted £16k for 24 Panels and Tesla Powerwall3 and Tesla Invester

Panels are JAM45441 LB 440W

 

12 Panels at 60 deg

12 Panels at 120 Deg

 

Current tarrif is Octopus Wholesale tracker circa 4,500 annual usage.

Will be an EV in 2 years time added to the above

 

Showing about half of generate being exported at about £700 a year.

 

So in essence no electricity bill except the standing charge.

 

I am struggling to see that this is a good value investment, or am I missing something?

 

[JohnMo]

£16k is a lot of money.

 

£16,000 / 700 is 23 years payback on exports

 

If you accept all 4500 kWh and £700 export is generated.

 

Not sure what you currently pay for your 4500kWh at 20p that's £900.

 

16000/(900+700) is 10 years.

 

If you are managing to get your average down to 15p with your tariff it's £675 a year, and still about 10 years.

 

 

 

[nod]

Also you need to add in maintenance and repair costs Like anything Things break and wear out 

[Mattg4321]

Tesla is overpriced imo. I don’t see how you can make it pay back. 
 

I’ve gone with Sunsynk inverter and batteries. No complaints yet (3 months in) and a lot less money. Should pay back in around 5 years or less depending on electricity prices for me (although labour was free)

[fromdownwest]

4 hours ago, Mattg4321 said:

Tesla is overpriced imo. I don’t see how you can make it pay back. 
 

I’ve gone with Sunsynk inverter and batteries. No complaints yet (3 months in) and a lot less money. Should pay back in around 5 years or less depending on electricity prices for me (although labour was free)

 

Thanks all for your input, my gut told me the same. I was just making sure I was not missing anything.

Can I ask where you purchased your hardware from please.

[Mattg4321]

16 minutes ago, fromdownwest said:

 

Thanks all for your input, my gut told me the same. I was just making sure I was not missing anything.

Can I ask where you purchased your hardware from please.

I used Phase Electrical wholesalers, who I use regularly through my business for non solar related materials. They now have a renewables division in Hastings. 

 

This is their 'retail' website https://www.green2go.co.uk/ I paid a lot less than the prices shown there, but I'm spending 4 figure sums there most months so no idea if that made a difference. ITS and Midsummer were a bit more expensive for me, but may not be for you.

 

Plenty of videos on Sunsynk on Youtube from the likes of eFixx. Time will tell how reliable it is, but it's definitely got a lot of plus points and can pretty much do everything.

 

 

[Dillsue]

Try CEF for your kit. They were selling longi 405s for £52 earlier this year yet cheapest panel on the green2go site seemed to be £70+

[JohnMo]

Remember to factor in with your deliberations, no MCS cert, you are unlikely to get any export payments. I chose to forego them, and export very little.

 

City Plumbing us also very cheap. 410W panels £47 plus vat.

[JamesPa]

On 23/08/2024 at 14:48, fromdownwest said:

I am looking at the option of a solar install via Octpus.

 

I have been quoted £16k for 24 Panels and Tesla Powerwall3 and Tesla Invester

Panels are JAM45441 LB 440W

 

12 Panels at 60 deg

12 Panels at 120 Deg

 

Current tarrif is Octopus Wholesale tracker circa 4,500 annual usage.

Will be an EV in 2 years time added to the above

 

Showing about half of generate being exported at about £700 a year.

 

So in essence no electricity bill except the standing charge.

 

I am struggling to see that this is a good value investment, or am I missing something?

 

Couple of points 'So in essence no electricity bill except the standing charge' is unlikely to be true.  With batteries you can shift generated capacity by a day or so to match load, but you cant shift it from summer to winter.  So you will almost certainly have an electricity bill in winter, particularly if you also have an ASHP.  

 

My advice is to do the sums on the battery (and as suggested above consider a cheaper brand).  Unlike solar panels there is no material ecological advantage, so you need to be making money on them to justify.  Unfortunately many solar installers are just not interested unless they also fit a battery, because that's where the margins currently are!   A solar diverter and your DHW tank make a very cheap 'battery', and a 200l tank of hot water heated from 10C to 50C is about 10kWh of storage capacity very cheaply.

 

If you are planning to get an EV and its at home during the day in summer then you will soak up quite a bit with that (weakening the case for a battery).  On the other hand if you can use a battery in conjunction with a ToU tariff there is potentially quite a bit to be gained. 

 

Basically its worth doing the sums for the mode in which you intend to operate, and of course check that the inverter (and any other relevant controls) are capable of operating in that mode.

 

My consumption is similar to yours.  I have 4kWp solar (from 2011) and couldn't make the case for a battery (unless cheapo + self installed) work even before I got an EV.  Now I have an EV the case is only getting weaker.

 

 

Edited August 28 by JamesPa